Donald S. Bryant (dsbryant@worldnet.att.net)
Thu, 07 Jan 1999 13:56:28 +0000
Judy,
What I think you are describing here is an attempt to define the color Gamut of a
color gum print. I assume you are making seperation transparences with Photoshop
on an ink jet printer (if I'm wrong please forgive me) which increases the
difficulty of controling variables defining each ouput media or devices color
space.
I'm by no means a Photoshop expert as I'm pretty much a neophyte but it seems to
me this is what all of this discussion of CMYK boils down to.
Don
Judy Seigel wrote:
> On Fri, 8 Jan 1999, Peter Charles Fredrick wrote:
>
> > Judy Wrote
> > .....Gum, as I may have said a time or 20, can get
> > everything in the negative if you let it. <<
> >
> > Lay this one to rest Judy it is getting distinctly boring, I think we all
> > agree with you and if we don't we dare not contradict :-)
>
> I wish I could get some of that respect around here, Peter, but the notion
> is far more prevalent than you might suppose. For instance, a major US
> company has those very words, "gum can't do fine detail" in its new
> catalog even as I write, and that goes to 80 thousand people... So one
> must do what one can.
>
> > .... most of these separation systems
> > are geared towards offset/ litho photo-mechanical printing, which is a far
> > cry from your beloved gum. I am convinced we will have to develop our own
> > parameters for photo/alt,
>
> Deciding after all to start with cyan (one of the books mentioned that as
> usual first -- I'd been using magenta), I printed my 4 different
> separations yesterday -- from the "medium black," "light black" "no black"
> and "undercolor removal" separations.
>
> What I found was what I knew in advance, but like raising children, what
> you know in advance is not that much help. Unless I rigidly define each
> variable, results are, let's say, fluid. For instance I used a cyan mix
> that has worked well with other separations in a different style, but for
> these separations it seemed much too strong. Perhaps there's a key
> somewhere about the chromatic intensity desired for each separation color,
> but meanwhile I'm in flux.
>
> After seeing the first one come out looking much too intense, I ruined the
> "experiment" by changing a variable mid-stream, that is, I cut down
> exposure from 75 units on the NuArc to 60, and when I redo, which I will,
> I'll cut down to 50. But of course the magenta exposure will probably have
> to go back up to 75, since red is slower. And, and, and, I further
> contaminated science by variable development, one of them overnight.
>
> So far, the one that makes the prettiest blue picture is the one with no
> black. None of the others has any white areas at all, but a fine blue mist
> over everything, even after very long soaks.
>
> The best I can hope for at this point is to make a wobbly zeroing in on
> mix, exposure and soak, the latter I'd like to keep to a half hour, or no
> more than an hour. In fact as a rule I've found digital exposures on the
> short side, so clearly I'm still way off the mark. Incidentally, for what
> it's worth, a 21-step on the side of one of these separations registered 8
> beautiful, smooth, firm, and distinct steps in the cyan mix at 60 NuArc
> exposure units.
>
> > IMHO it is very difficult to compare separation printers, if not impossible
> > at times to gain meaningful information by just eyeballing the negs, only
> > by printing these little devils can an accurate assessment be made.
>
> Oh boy, you can say that again. And, as noted above, HOW you print them
> puts an infinity of possibilities in the path of each. With a short enough
> exposure, for instance, I probably could have gotten clear areas in the
> other 3 separations.
>
> > No thank you ! it is nice to find someone reading and reacting to my
> > emails,I don't mind Bob Maxey shouting at me or you being very sweet to me,
> > it is the lurking silence that I find unnerving :->
>
> I can relate to that. It's like, did my piteous question -- or my
> brilliant synopsis -- fall into a well somewhere?
>
> > Most photomechanical systems , print the black first, however many fine art
> > printmakers favour printing the black information block last.Here we are up
> > against the same problem again and again one persons meat is anothers
> > poison
>
> I decided at this early stage to print black last because it gave me a
> two-fer, that is I could see what it would look like without the black
> without having to do a whole new set.
>
> But, the black problem remains. Yesterday I ran a test of 7 blacks,
> everything in all the boxes. The ivory blacks, whether gouache or
> watercolor, were very brown, and tended to flake even at weak
> concentrations. It turned out I didn't have MARS black, but something
> called Lunar black, which was the pits. A mix of indigo and sepia that
> looked a little like black also flaked badly when used strong enough to
> resemble black. The only color that worked and was neutral in tone was the
> Neutral Tint, as was so egregious in the previously mentioned print. I've
> found in the past that lamp black doesn't clear in gum, though I guess
> I'll try that and any others recommended again before settling on the
> Neutral Tint.
>
> > Get your scanner Judy, it opens a new world, incidentally it is nice to see
> > you moving away from your one coat gum fixation, and embracing the
> > wonderful world of colour.
> >
>
> I hope I haven't been giving the impression that I only do one coat gum...
> True, if I could get an unlimited supply of Buxton, it would be hard to
> tear myself away from the one coat mode, which it does so lusciously, you
> wouldn't believe. I simply was annoyed (understatement) by the claim that
> you can't do one coat -- as were Demachy & Puyo, by the way. Puyo says oh
> those foreigners (les etrangeres), by which he meant the Austrians and
> Germans, have to do a lot of coats, but we FRENCH do not!
>
> I mostly do many coats, or rarely less than two, in many colors, sometimes
> "spot" color. Lately by the way, and finally, after a number of aborted
> tries, I've gotten good results with *fake* full color, using the CMY with
> variations in exposure and brushing. It's tricky, a lot of failure (like
> what else is new), but when it works, a real hit...
>
> OK, time to quit before I attract Panix's evil eye & it crashes me. Thanks
> for the interest & the moral support, Peter... I hope to have some
> further developments, so to speak, to follow soon.
>
> Judy
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